JP2006299371A - Method for producing fine metal structure, and fine metal structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a fine metal structure where electroplating can be performed to the pattern of the film to be worked formed by a nano-imprint process without removing a residue film. <P>SOLUTION: (1) A die 2 in which a fine rugged pattern is formed is pressed against the film 3 to be worked in a fluidized state made of a high polymer film having electric conductivity; (2) the film to be worked in a fluidized state is hardened, and the die is peeled from the hardened film to be worked, so as to obtain the film to be worked to which the rugged pattern of the die is transferred, and having a structure pattern; (3) plating is performed with the film to be worked as an electrode, and each plating metal 4 is deposited on each recessed part of the pattern in the film to be worked having the structure pattern; and (4) each deposited plating metal is separated from the film to be worked, so as to produce each fine metal structure 5. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention is a micro mechanical structure such as a functional part for a semiconductor chip such as an LSI, a micro machine part such as various actuators or a probe head, and a micro part used for MEMS (Micro Electro Mechanical Systems). The present invention relates to a metal structure. And it is related with the manufacturing method of the fine metal structure.

  As a method for forming a fine pattern, a nanoimprint method, which has a resolution that is not limited by the limitations of conventional machining and optical lithography and is a lower cost method, has recently attracted attention. For example, according to the contents disclosed in Patent Document 1, as shown in FIG. 5, a substrate 101 on which a film 103 to be processed is formed and a mold 102 on which a fine uneven pattern of about 25 nm or less is formed are prepared. (See FIG. 5A). Here, the film to be processed 103 is a resist film made of a thermoplastic resin such as polymethyl methacrylate formed on the surface of the substrate 101.

  Then, after the film 103 to be processed is softened by being heated to the glass transition point or higher, the mold 102 is pressed against the film 103 to be processed (see FIG. 5B). Then, after the film to be processed 103 is solidified by cooling to the glass transition point or lower, the mold 102 is peeled off from the solidified film 103 to be processed, and a reversal pattern of the fine uneven pattern of the mold 102 is covered. Transfer to the processed film 103 (see FIG. 5C).

  Moreover, according to the content currently disclosed by patent document 2, as shown in FIG. 6, the board | substrate 101 with which the to-be-processed film | membrane 103 was formed in the surface, and light transmissive materials, such as quartz and Pyrex (registered trademark) A mold 102 is prepared (see FIG. 6A). Here, the film 103 to be processed is made of a photocurable material such as a UV curable resin. Then, the mold 102 is pressed against the workpiece film 103 (see FIG. 6B). Then, the mold 102 is peeled off from the processed film 103 cured by irradiating light through the mold 102, and a reversal pattern of the fine uneven pattern of the mold 102 is transferred to the processed film 103 (see FIG. 6C). ).

  As described above, in the nanoimprint method, if a mold on which a desired concavo-convex pattern is formed can be prepared, a fine concavo-convex pattern can be replicated by an extremely simple process. Since the mold is pressed against the stationary film, the uneven pattern can be accurately transferred even if the film is thin and has a large area. Can do. As the mold, a silicon or quartz mold manufactured by an electron beam exposure technique and an etching technique having a resolution of several nanometers to several tens of nanometers, a metal mold using these molds as a master, a LIGA (Lithographie having a resolution of several micrometers). Metal molds produced by Galvanoformung Adformung) technology can be used.

  Next, a method for producing a fine metal structure by applying the nanoimprint method will be described. For example, as shown in FIG. 7, first, a film to be processed 103 to which a reversal pattern of a fine uneven pattern of the mold 102 is transferred by the nanoimprint method described above is prepared (see FIG. 7A). The processed film 103 is formed on a conductive substrate 101.

  Then, a pattern concave portion is formed in the film to be processed onto which the concave / convex pattern of the mold has been transferred, and the residual film formed on the bottom surface of the pattern concave portion is removed by etching, excimer laser, or the like (see FIG. 7B). Next, electrolytic plating is performed using the exposed conductive substrate 101 as an electrode, and a plating metal 104 is deposited in the pattern concave portion of the film 103 to which the reversal pattern of the fine concavo-convex pattern of the mold 102 is transferred (FIG. 7). (See (C)). Then, the processed film 103 is removed by plasma ashing or an organic solvent, and the substrate 101 is removed by etching to obtain a fine metal structure 105 (see FIG. 7D).

  FIG. 8 shows another method for producing a fine metal structure by applying the nanoimprint method. First, a processed film 103 to which a reversal pattern of a fine uneven pattern of the mold 102 is transferred by the nanoimprint method described above is prepared, and the processed film 103 is separated from the substrate 101 (see FIG. 8A).

  Next, the surface to which the uneven pattern of the separated processed film 103 is transferred is bonded to a conductive second substrate 107 (see FIG. 8B). Then, the surface of the processed film 103 where the uneven pattern is not transferred is removed by polishing or etching until the uneven pattern transferred to the processed film 103 is opened (see FIG. 8C). Then, electroplating is performed using the conductive second substrate 107 as an electrode, and the plating metal 104 is deposited in the pattern recess of the processed film 103 to which the reverse pattern of the fine uneven pattern of the mold 102 is transferred (FIG. 8). (See (D)). After that, the film 103 to be processed is removed by plasma ashing or an organic solvent, and the substrate 101 is removed by etching to obtain a fine metal structure 105 (see FIG. 8E).

US Pat. No. 5,772,905 JP 2000-194142 A

  However, in the conventional nanoimprint method, in order to prevent damage to the mold, the mold can only be pressed to the film to be processed to a depth at which the mold does not contact the substrate. As a result, a residue film was formed on the bottom of the pattern concave portion of the film to be processed. For this reason, in order to perform electroplating using the conductive substrate under the film to be processed or the conductive film formed on the substrate surface as an electrode, the residual film is etched, excimer laser, polished, etc. Therefore, there is a problem that productivity is poor and processing accuracy is lowered.

  Accordingly, an object of the present invention is to provide a method for producing a fine metal structure capable of performing electroplating on a pattern of a film to be processed formed by a nanoimprint method without having to remove a residual film.

  Moreover, it is providing the manufacturing method of the fine metal structure which manufactures a fine metal structure with sufficient productivity. Another object of the present invention is to provide a method for manufacturing a fine metal structure that can reliably prevent the mold and the substrate from contacting each other.

In order to achieve such an object, the first aspect of the present invention provides:
1) Press a mold with a fine concavo-convex pattern formed on a substrate to be processed in a fluid state made of a conductive polymer film,
2) Curing the film to be processed in the fluidized state, peeling the mold from the cured film to be processed, and transferring the uneven pattern of the mold to obtain a film to be processed having a structure pattern.
3) performing plating using the processed film as an electrode, and depositing a plating metal on the pattern recess of the processed film having the structure pattern;
4) separating the deposited plated metal from the film to be processed;
It is a manufacturing method of a fine metal structure which manufactures a fine metal structure.

  For example, a conductive resin composition is used as the film to be processed. An insulating material is used as the substrate.

  The mold is peeled to obtain a work film having the structure pattern, plating is performed using the work film as an electrode, the plating metal on the front and back of the work film and the substrate are removed, and the work film is removed. The plating metal removed and deposited in the pattern recess is separated from the film to be processed. In addition, after removing the mold to obtain a film to be processed having the structure pattern, separating the substrate from the film to be processed, the film to be processed except for the pattern concave portion of the film to be processed having the structure pattern. It is preferable to coat the processed film with an insulating material, perform plating using the processed film as an electrode using the insulating material as a mask, and deposit a plating metal in the pattern recess. Furthermore, it is preferable that the film to be processed is thicker than the height of the uneven pattern of the mold.

  A second aspect of the present invention is a fine metal structure produced by using the method for producing a fine metal structure according to any one of claims 1 to 6.

  According to the present invention, a mold having a fine uneven pattern formed is pressed against a processed film made of a conductive polymer film on a substrate. Electrolytic plating can be applied to the membrane. Therefore, the nanoimprint method does not require a process of forming a structure pattern on a film to be processed onto which the concave / convex pattern of the mold has been transferred, and removing the residual film formed on the bottom of the pattern recess by etching, excimer laser, polishing, etc. Providing a method of manufacturing a fine metal structure with high processing accuracy that can be electroplated on the structure pattern of the film to be processed, improving productivity and preventing deterioration of processing accuracy due to additional machining can do.

  Further, the process for obtaining the fine metal structure does not depend on the amount of the residual film formed on the bottom of the pattern recess of the film to be processed having the structure pattern. Therefore, the film to be processed can be formed sufficiently thicker than the height of the uneven pattern of the mold. Therefore, the mold does not contact the substrate, and the mold can be reliably prevented from being damaged.

  In addition, if a conductive resin composition used for molding is used as the film to be processed, the film to be processed to which the concave / convex pattern of the mold is transferred can be made conductive while maintaining high moldability. And a method for producing a fine metal structure with high processing accuracy can be provided.

  If an insulating substrate is used, the plating metal is not deposited on the substrate in the electrolytic plating step, and only the substrate can be easily removed after the electrolytic plating. Therefore, it becomes possible to remove the film to be processed from both the front surface and the back surface, and it is possible to provide a method for manufacturing a fine metal structure with improved efficiency of removing the film to be processed and improved productivity.

  In addition, if a processed film having a concavo-convex pattern transferred thereon is obtained by peeling the mold and the substrate is separated from the processed film, it becomes easier to handle the processed film as a single unit, and the bottom of the pattern concave portion of the processed film Thus, it is possible to provide a method for producing a fine metal structure in which productivity is improved by removing the substrate directly from the film to be processed without requiring a step of removing the residual film generated in the process.

  In addition, if an insulating material is selectively applied to the film to be processed as a mask for electrolytic plating, a region where no plating metal is deposited can be formed on the film to be processed. Therefore, a region that becomes a starting point when removing the film to be processed is widened, and it is possible to provide a method for manufacturing a fine metal structure that improves the removal efficiency of the film to be processed and improves the productivity.

  Further, when the film to be processed is thicker than the height of the concave / convex pattern of the mold, it is possible to provide a method for manufacturing a fine metal structure that reliably prevents contact between the mold and the substrate and does not break the mold.

  Furthermore, according to this invention, the fine metal structure which has the effect mentioned above can be provided.

The best mode of the present invention will be described below with reference to the drawings.
1A to 1F show a manufacturing process of a fine metal structure according to the present invention.

  In the process of manufacturing the fine metal structure, first, a film to be processed 3 is formed on the substrate 1 by spin coating or sheet bonding, and the mold 2 is disposed at a position facing the substrate 1 (see FIG. 1 (A)).

  As the substrate 1, various metal substrates can be used, and a substrate having a certain strength such as a silicon substrate, a sapphire substrate, or a quartz substrate can be used. It is preferable to use an insulating substrate, and here, a silicon substrate which is an insulating substrate is used.

As the processed film 3 formed thereon, a conductive polymer such as a conductive resin composition can be used. The conductive resin composition is obtained by mixing and dispersing a conductive filler such as carbon, carbon fiber, fine metal particles, and fibrous metal in a polymer resin material such as a thermoplastic resin and a thermosetting resin, and then volume resistivity. Has a conductivity as high as that of a metal such that is 10 ⁻² Ω · cm or less. As the film 3 to be processed, it is preferable to use a conductive resin composition for molding. Here, a conductive resin composition for molding processing in which a low-melting-point metal as a conductive filler or an alloy thereof is mixed and dispersed in a thermoplastic resin as metal film 3 as a dispersion auxiliary material, as work film 3 Use things. Its volume resistivity is 10 ⁻⁴ Ω · cm.

  Further, the film to be processed 3 may be formed with an arbitrary thickness, but is preferably formed with a thickness sufficiently thicker than the height of the concavo-convex pattern of the transferred mold 2. 150 μm.

  On the other hand, the mold 2 can be manufactured by a MEMS (Micro Electro Mechanical Systems) manufacturing technique such as a LIGA (Lithographie Galvanoformung Adformung) technique or a silicon dry etching technique. Here, the die 2 is made of nickel manufactured by LIGA technology, that is, X-ray lithography and electroforming, and has, for example, at least one pattern of a spring structure having a height of 100 μm and a width of 20 μm. .

  In order to improve the releasability of the mold 2 from the film 3 to be processed, it is preferable to perform a mold release treatment on the surface of the mold 2. Here, the surface of the mold 2 is coated with a fluorine-based mold release agent (“OPTOOL DSX” manufactured by Daikin Industries, Ltd.).

  Next, the film to be processed 3 is heated to the glass transition point or higher and softened, and the mold 2 is pressed against the film to be processed 3 that is softened and in a fluid state (see FIG. 1B). The mold 2 is formed with a fine uneven pattern. Here, the mold 2 is pushed in at a pressure of 50 MPa.

  Then, the processed film 3 is cured by cooling to a glass transition point or lower, and the mold 2 is peeled off from the cured processed film 3 so that the uneven pattern of the mold 2 is transferred to have a structure pattern. A film to be processed 3 is obtained (see FIG. 1C). For example, a thermosetting resin may be used as the work film 3 and may be cured by heating. Moreover, you may harden | cure by irradiating active energy, such as UV light and an electron beam, using active energy curable resins, such as UV curable resin and an electron beam curable resin, as a to-be-processed film.

  Thereafter, electrolytic plating is performed using the film to be processed 3 as an electrode, and a plating metal 4 is deposited in the pattern recesses of the film to be processed 3 having a structure pattern (see FIG. 1D). As this plating metal 4, various plating metals can be used. Here, a nickel sulfamate bath is used to deposit a nickel film.

  Next, the substrate 1 is separated from the plated metal on the front and back sides of the film 3 to be processed by removing by polishing or etching (see FIG. 1E).

  Then, the thickness of the plating metal 4 is adjusted by removing it by polishing or etching, and then the plating metal 4 deposited on the pattern recesses by an organic solvent or plasma ashing is separated from the film 3 to be processed. And the fine metal structure 5 is obtained by selectively removing from both surfaces of the back surface (see FIG. 1F).

  In the above-described example, a silicon substrate which is an insulating substrate is used as the substrate 1, and the substrate 1 is removed by polishing or etching to separate all of the substrate 1 from the film 3 to be processed. However, as shown in FIG. 2A, by using the substrate 1 having the insulating thin film 7 formed on the surface and removing the insulating thin film 7 as shown in FIG. Alternatively, the substrate 1 may be separated from the film 3 to be processed.

  As described above, if the film to be processed 3 is formed of a conductive polymer film, the uneven pattern of the mold 2 can be transferred to perform electroplating on the subsequent film to be processed, and etching. The fine metal structure 5 can be obtained from the film to be processed 3 onto which the concave / convex pattern of the mold 2 has been transferred, without passing through the residual film removal step such as excimer laser and polishing. Therefore, productivity can be improved and a reduction in processing accuracy due to additional machining can be prevented.

  Moreover, if the conductive resin composition used for molding is used as the film to be processed, the film 3 to which the concave / convex pattern of the mold 2 is transferred is made conductive while maintaining high moldability. be able to. Therefore, the fine metal structure 5 can be obtained with higher processing accuracy.

  Furthermore, the process for obtaining the fine metal structure 5 does not depend on the amount of the residual film formed on the bottom of the pattern recess of the film to be processed having the structure pattern. Therefore, the film 3 to be processed can be formed sufficiently thicker than the height of the uneven pattern of the mold 2. Therefore, the mold 2 does not come into contact with the substrate 1 and the mold 2 can be reliably prevented from being damaged.

  Furthermore, if an insulating substrate is used as the substrate 1, no plating metal is deposited on the substrate 1 in the electrolytic plating step, and only the substrate 1 can be easily removed after electrolytic plating. Therefore, the film to be processed 3 can be removed from both the front and back surfaces, and the removal efficiency of the film to be processed 3 can be increased. That is, productivity can be improved.

3A to 3D show another manufacturing process of the fine metal structure according to the present invention.
In the process of manufacturing this fine metal structure, a film to be processed 3 is formed on the substrate 1 by spin coating or sheet pasting, as in the above-described example, and a mold is formed at a position facing the substrate 1. 2 is softened by heating the film to be processed 3 to the glass transition point or higher, and the mold 2 on which a fine uneven pattern is formed is pressed against the film to be processed 3 in a fluid state, and then cooled or heated. The mold 2 is peeled from the cured film 3 that has been cured by irradiating with active energy or the like, and the processed film 3 to which the uneven pattern of the mold 2 has been transferred is obtained (see FIG. 3A).

  Next, after removing the substrate 1 by etching or polishing, the insulating material 6 is selectively applied to the film to be processed as a mask for electrolytic plating, except for the pattern recesses of the film to be processed having a structure pattern. It is coated by a method such as spin coating, spray coating, or brush coating (see FIG. 3B).

  Then, electrolytic plating is performed using the film to be processed 3 as an electrode, and the plating metal 4 is deposited on the pattern recesses of the film to be processed 3 having a structure pattern, and then removed by polishing or etching to reduce the thickness of the plating metal 4. Adjust (see FIG. 3C).

  Thereafter, the insulating base 6 is removed by an organic solvent or plasma ashing, and then the film 3 to be processed by an organic solvent or plasma ashing is used as a starting point from a region where the insulating base 6 is applied and no plating metal is deposited. Are also selectively removed to obtain a fine metal structure 5 (see FIG. 3D).

  As described above, if the insulating material 6 is selectively applied to the film to be processed 3 as a mask for electrolytic plating, a region where no plating metal is deposited can be formed on the film to be processed 3. . Therefore, the starting region for removing the film to be processed is widened, the removal efficiency of the film to be processed 3 can be increased, and the productivity can be improved.

4A to 4D show still another manufacturing process of the fine metal structure according to the present invention.
In the process of manufacturing the fine metal structure, when the thickness of the processed film 3 is sufficiently higher than the height of the concave / convex pattern of the mold 2, after the concave / convex pattern of the mold is transferred to the processed film 3, The processed film 3 formed on the support 8 that is a substrate is peeled off from the support 8.

  For example, the sheet-like processed film 3 having a thickness of 1 mm is held by the support 8, and the mold 2 is disposed at a position facing the support 8 (see FIG. 4A). As the support 8, not only various substrates having a certain strength but also components of an apparatus for producing the fine metal structure of the present invention can be used. Here, the heating mechanism of the apparatus for producing the fine metal structure of the present invention is used as the support 8.

  And like the example mentioned above, for example, the processed film 3 is softened by heating to a glass transition point or higher, and the mold 2 on which a fine uneven pattern is formed is pressed against the processed film 3 in a fluid state, The mold 2 is peeled from the processed film 3 that has been cured by cooling, heating, or irradiation of active energy, whereby the concave / convex pattern of the mold 2 is transferred to obtain the processed film 3 having a structure pattern (see FIG. 4 (B)). The mold 2 has a pattern having a height of 150 μm, for example.

  Next, after peeling the processed film 3 from the support 8, electrolytic plating is performed using the processed film 3 as an electrode, and the plating metal 4 is deposited in the pattern recesses of the processed film 3 having the structure pattern (FIG. 4 (C)). In addition, in order to make peeling of the to-be-processed film 3 from the support body 8 easy, it is preferable to perform the mold release process on the surface of the support body 8 with a mold release agent or the like. In addition, when performing electroplating, an insulating material (not shown) can be selectively applied to the film 3 to be processed as a mask for electroplating.

  Then, the processed film 3 and the plated metal 4 are removed by polishing or etching to adjust the thickness of the plated metal 4, and then the processed film 3 is selectively removed by an organic solvent or plasma ashing to obtain a fine metal. A structure 5 is obtained (see FIG. 4D).

  As described above, if the mold 2 is peeled off to obtain the film to be processed 3 to which the concavo-convex pattern is transferred, and the support 8 that is the substrate is separated from the film to be processed 3, the film to be processed 3 is handled alone. This makes it easy to peel the support 8 directly from the film to be processed 3 without performing a removal step such as etching or polishing, thereby improving productivity. Further, when the film to be processed 3 is thicker than the height of the concave / convex pattern of the mold 2, the contact between the mold 2 and the support 8 can be reliably prevented.

(A) thru | or (F) is a manufacturing-process figure of the fine metal structure by this invention. It is a partial process diagram of another manufacturing process. It is a change partial process figure of another manufacturing process. It is another manufacturing process figure. It is a manufacturing-process figure of the fine pattern using the conventional nanoimprint method. It is a manufacturing-process figure of another fine pattern using the conventional nanoimprint method. It is the conventional manufacturing process figure which applies a nanoimprint method and manufactures a fine metal structure. It is another conventional manufacturing process diagram.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Substrate 2 Type 3 Workpiece film 4 Plating metal 5 Fine metal structure 6 Insulating material 7 Insulating thin film 8 Support

Claims (7)

1) Press a mold with a fine concavo-convex pattern formed on a substrate to be processed in a fluid state made of a conductive polymer film,
2) Curing the film to be processed in the fluidized state, peeling the mold from the cured film to be processed, and transferring the uneven pattern of the mold to obtain a film to be processed having a structure pattern.
3) performing plating using the processed film as an electrode, and depositing a plating metal on the pattern recess of the processed film having the structure pattern;
4) separating the deposited plated metal from the film to be processed;
A method for producing a fine metal structure, comprising producing a fine metal structure.   The method for producing a fine metal structure according to claim 1, wherein a conductive resin composition is used as the film to be processed.   The method for manufacturing a fine metal structure according to claim 1, wherein an insulating material is used as the substrate.   The mold is peeled to obtain a work film having the structure pattern, plating is performed using the work film as an electrode, the plating metal on the front and back of the work film and the substrate are removed, and the work film is removed. 4. The method for manufacturing a fine metal structure according to claim 1, wherein the plating metal removed and deposited in the pattern concave portion is separated from the film to be processed.   The processed film having the structure pattern is obtained by peeling the mold, and after separating the substrate from the processed film, the processed film except for the pattern recess of the processed film having the structure pattern. 5. The fine metal according to claim 4, wherein plating is performed using the insulating material as a mask and the film to be processed as an electrode to deposit a plating metal in the pattern recess. Manufacturing method of structure.   The method of manufacturing a fine metal structure according to claim 1, wherein the film to be processed is thicker than the height of the uneven pattern of the mold.   A fine metal structure produced by the method for producing a fine metal structure according to any one of claims 1 to 6.

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